Strategy

The following solution may not be very fast or organized. Improvements welcome. Like all Sokoban levels it can be solved without making any boulders 'stick'.

All boulders are replaced by letters so they can be referred to. Moving the boulders is shortened to r for right, l for left, u for up, d for down. An asterisk is used to denote the last move filled a hole (and thus removed the boulder from the game). So "N ddrr*" means move boulder N two times down and two times to the right into a hole.

Arrange the boulders in the middle and lower areas so they can be pushed into holes later